Diabetic ketoacidosis
Diabetic ketoacidosis is a life-threatening hyperglycemic crisis of near-absolute insulin deficiency, most common in type 1 diabetes, producing an anion-gap ketoacidosis from unrestrained lipolysis and osmotic diuresis from severe hyperglycemia. It is diagnosed by hyperglycemia, ketonemia, and an anion-gap metabolic acidosis, and treated with intravenous isotonic saline, an intravenous regular insulin bolus and infusion, and aggressive potassium repletion guided by frequent electrolyte monitoring.
- Topic reviewThe full article, organized the way the exam asks it.
- ABIM-format MCQsVignettes with an explanation for every wrong answer.
- Key factsThe numbers and thresholds worth memorizing, up front.
- AI tutorMedBrain answers the question you're stuck on.
What this article covers
- Overview
A life-threatening hyperglycemic crisis defined by the triad of hyperglycemia, ketonemia, and an anion-gap metabolic acidosis, resulting from a relative or absolute deficiency of insulin combined…
- Epidemiology
Occurs across all ages but is most frequent in patients with type 1 diabetes younger than 65 years, reflecting the near-absolute insulin deficiency characteristic of that population.
- Risk factors
Missed or insufficient insulin dosing, the most common precipitant, including nonadherence and insulin pump or infusion-site failure.
- Pathophysiology
Profound insulin deficiency, whether absolute (type 1 diabetes) or relative to a major physiologic stress, removes the normal brake on lipolysis and hepatic gluconeogenesis and glycogenolysis.
- Clinical features
DKA is recognized by the combination of hyperglycemia, ketosis, and metabolic acidosis in a patient who typically presents acutely ill, with symptoms usually developing within 24 hours…
- Differential diagnosis
Hyperglycemic hyperosmolar state: shares hyperglycemia and dehydration, but distinguished by minimal or absent ketosis and acidosis, a much higher glucose, and typically occurs in older patients with…
- Diagnosis
The diagnosis is established by the triad of hyperglycemia (plasma glucose typically 250 mg/dL, though euglycemic DKA can occur with SGLT2 inhibitor use), ketonemia (beta-hydroxybutyrate typically…
- Management
First, begin fluid resuscitation with 0.9% saline at 1 L/h, continuing isotonic saline if the patient remains severely hypovolemic, and switch to 0.45% saline at 250-500 mL/h once the corrected serum sodium normalizes or is high.
- Complications
Cerebral edema, the leading cause of death in DKA, with a mortality rate exceeding 20%; risk is reduced by avoiding overly rapid correction of serum osmolality and glucose.
- Prognosis
With prompt fluid, insulin, and electrolyte therapy, most episodes of DKA resolve without permanent sequelae, particularly in adults without cerebral edema.
- Prevention
Provide structured diabetes self-management education at diagnosis and at each care transition, with particular attention to sick-day insulin dosing rules so patients never stop insulin during illness.
Read the whole article
Subscribing to Internal Medicine opens every article, the full question bank and MedBrain, on the web, iPhone and Android.
Related articles
- Hyperosmolar hyperglycemic state
Hyperosmolar hyperglycemic state is a life-threatening hyperglycemic crisis of older patients with type 2 diabetes, marked by extreme hyperglycemia and profound dehydration without significant ketoacidosis, because residual insulin secretion suppresses lipolysis even as it fails to control glucose. It is diagnosed by marked hyperglycemia (often >600 mg/dL) with plasma hyperosmolality above 320 mOsm/kg and minimal ketosis, and treated with aggressive isotonic fluid resuscitation, intravenous regular insulin, and careful potassium repletion.
- Type 1 diabetes mellitus
Type 1 diabetes mellitus is an insulin-deficient state from autoimmune (type 1A) or idiopathic (type 1B) destruction of pancreatic beta cells, presenting with hyperglycemia that can range from mild to life-threatening diabetic ketoacidosis. Diagnosis combines standard glycemic criteria with autoantibody testing (GAD65, IA-2), and lifelong insulin therapy, generally as a basal-bolus regimen, is required from diagnosis, with self-monitoring or continuous glucose monitoring to guide dosing.
- Insulin therapy in diabetes mellitus
Insulin therapy replaces or supplements endogenous insulin to control hyperglycemia, and is lifelong and mandatory in type 1 diabetes because of absolute beta-cell failure, while in type 2 diabetes it is added when oral and noninjectable agents fail to reach glycemic goals. First-line therapy is a basal-bolus regimen started at 0.4-1.0 units/kg/day in type 1 diabetes, or basal insulin glargine 10 units/day (or 0.1-0.2 units/kg/day) in type 2 diabetes, titrated to a fasting glucose target.
- Type 2 diabetes mellitus
Type 2 diabetes is hyperglycemia from insulin resistance with progressive relative insulin deficiency, diagnosed by a hemoglobin A1c of 6.5% or higher, a fasting glucose of 126 mg/dL or higher, or a 2-hour oral glucose tolerance test value of 200 mg/dL or higher. First-line treatment is lifestyle modification plus metformin, with an SGLT2 inhibitor or GLP-1 receptor agonist added early for patients with atherosclerotic disease, kidney disease, or heart failure.